The present invention relates to systems for transporting passengers or materials by means of cable-drawn non-motorized vehicles, these systems having the following characteristics:
the vehicles are supported and guided by a track specifically for this purpose and not by the cable; PA0 the vehicles may be coupled and uncoupled from a cable moving at constant speed, to slow down or stop at a station, for example. PA0 relatively simple automatic control facilities since there is no risk of vehicles coupled to the same cable colliding between stations; PA0 low energy consumption due to the low weight of the non-motorized vehicles. PA0 the reversible coupling of the vehicles to the cable by means of two-branch clamps comprising a "fixed" part connected to the chassis of the vehicle, a "moving" part which is connected to the fixed part and which rolls without slip on the cable and, in at least one branch, a device for resisting relative movement between the fixed and moving parts; PA0 the provision at each end of a section of the track in which the vehicles are drawn by a cable of an actuating device which co-operates with a device controlling the clamp so as to close the clamp on entry to and open the clamp on exit from said section; PA0 the provision at the entry end of a section of the track in which the vehicles are drawn by a cable of a device for bringing the clamp on the vehicle and the cable into closer proximity with one another. PA0 a clamp in which the braking device is operated by closing the clamp, PA0 a "coil-type" weighing mechanism.
Some 100 years ago the first systems of this type replaced animal traction on tramways and were used for certain underground railways (Glasgow). Most such systems have disappeared with advances in electric traction, and the San Francisco cable car is perhaps the only system of this type still in operation. Its operation is extremely simple, as disclosed in German Pat. No. 28155.
The vehicles are guided by rails laid on the ground and entrained by a cable moving at constant speed. When the driver wishes to stop at a station he opens the clamp which couples the vehicle to the cable and brakes the vehicle wheels. To depart, the clamp grips the cable and the vehicle gradually accelerates to the speed of the cable. The progressive coupling action is obtained either by friction between the jaws of the clamp and the cable or by braking pulleys which replace such jaws and which roll without slip on the cable. Various mechanisms of this type are disclosed in French Pat. Nos. 695425, 1359331 and 1554769, and in German Pat. No. 532,413.
Since the end of the sixties increasing traffic congestion in towns has led to increasing research on urban transport systems using small automatic vehicles. Cable traction systems have again become relevant and offer two major advantages for small vehicle systems:
The most advanced of this new generation of automatic transport systems using cable-drawn vehicles would seem to be that disclosed in French Pat. No. FR 71 12413. Vehicles guided by rails laid on the ground are coupled to the high-speed cable by means of a conventional clamp with jaws. The coupling action is instantaneous as relative slip between the clamp and cable is virtually impossible. If the speed of a vehicle is slightly different from that of the cable at the moment the vehicle couples on to the cable, the vehicle cannot absorb this speed difference by swinging, like the suspended cabins of cable railways, and the sudden shock may be violent in intensity. Passenger safety therefore calls for strict synchronization of the vehicle and cable speeds at the moment of coupling. Automatic control of the coupling action in association with such synchronism would seem to be a difficult problem, especially in the case of vehicles following one after the other at short intervals.